Frozen Zoo: a collection of permafrost samples containing viable protists and their viruses

Permafrost, frozen ground cemented with ice, occupies about a quarter of the Earth’s hard surface and reaches up to 1000 metres depth. Due to constant subzero temperatures, permafrost represents a unique record of past epochs, whenever it comes to accumulated methane, oxygen isotope ratio or stored mummies of animals. Permafrost is also a unique environment where cryptobiotic stages of different microorganisms are trapped and stored alive for up to hundreds of thousands of years. Several protist strains and two giant protist viruses isolated from permafrost cores have been already described. In this paper, we describe a collection of 35 amoeboid protist strains isolated from the samples of Holocene and Pleistocene permanently frozen sediments. These samples are stored at −18°C in the Soil Cryology Lab, Pushchino, Russia and may be used for further studies and isolation attempts. The collection strains are maintained in liquid media and may be available upon request. The paper also presents a dataset which consists of a table describing the samples and their properties (termed "Sampling events") and a table describing the isolated strains (termed "Occurrences"). The dataset is publicly available through the GBIF portal.

Region dependent 13C, 15N, 18O isotope ratios in the cow milk

We present measurements of stable carbon, nitrogen and oxygen isotope ratio values in cow milk, forage and drinking water collected in Belarus. Milk, water and forage were sampled in Brest, Gomel, Grodno, Minsk and Mogilev regions during summer and winter seasons. δ13C and δ15N values in dried milk samples ranged from –30.2 to – 20.0‰ and from +3.63 to +5.66‰, respectively. The lowest δ13C values were obtained in the Mogilev region in summer. δ18O values in drinking water were quite constant (δ18O = +9.83±0.63‰), but the δ18O pattern in milk water changed across the regions.